Shell fuse



May 5, 1925.

SHELL FUSE F. G. L. JOHNSON Fild N'ov. v, 1924 W YW Patented May 5, 1925.

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FREDERICK GEOFFREY LEES JOHNSON, OF WESTMINSTERQLONDON, ENGLAND, AS- SIGNOR TO VICKERS LIMITED, OF LONDON, ENGLAND, A BRITISH COMPANY.

SHELL FUSE.

Application filed November 7, 1924. Serial No. 748,383.

retained in place by an inertia member and which, after they have been released by .the said member on shock of discharge, move outward under the influence of centrifugal force so as to permit the firing needle or pin to be moved rearward to ignite' the detonator when the shell strikes an object.

According to the present invention a light shearing wire is provided which passes through holes in the needle carrier of larger size than the wire so that the said wire normally lies out of contact with the front end of the said holes and thus cannot be subjected to shearing stresses if the needle carrier should receive a heavy blow during transport or during the loading of the gun. hen however the said centrifugal device has moved into the inoperative position after the shell has left the muzzle of the gun, the air pressure on the front surface of the carrier moves the latter rearward slightly and brings the front ends of the aforesaid holes into contact with the shearing wire. This wire, being of small diameter and made of readily shearable metal (copper for example), becomes sheared on impact of the front surface of the needle carrier with even a slight obstruction such as balloon fabric.

The said carrier is preferably composed of two light metal pressings of cup shape fitting one within the other to form a hollow member with the rear wall of which the needle is made integral. The said carrier is thus of very light construction and shoulder in an axial hole in which the needle carrier is disposed, this disc when deformed by hand after the parts have been assembled holding the needle carrier against the aforesaid collar halves without impeding the rearward movement of the disc and the needle carrier by air pressure and on impact as aforesaid.

In order that the said invention may be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawing which is an axial section of a fuse constructed in accordance With'this invention.

A is the fuse body, A is the nose screwed into the fuse body,,.B is the detonator and B is the detonator holder screwed into the fuse body A.v G, G are the two cup-shaped portions of the needle carrier, whichportions fit together as shown to form a hollow member of very light weight. The rear portion C carries the needle '0 and the for-, ward part of this portion 0 bears against a shoulder a in the nose A This forward I part is formed with a recess 0 (shown in dotted lines) to receive a pin A projecting from thenose A into the axial hole in which the needle carrier is disposed; this v arrangement prevents the needle carrier from rotating with respect to the nose A during the flight of the shell. The said pin and recess also prevent shearing of the shearing wire D during assembly and also serve to position the needle carrier so as to facilitate the assembly of the shearing wire. This shearing wire passes transversely through the nose A and through the holes 0 0 in the sidewalls of the carrier parts C, C these holes being made considerably larger in diameter than the shearing wire D so that the latter is normally out of contact with the .front and rear ends of i these holes. It will be understood that the needle carrier is. placed in position from the rear and thatthe shearingwire s then inserted and suitably secured in position.

loo 7 E, E are two halves "of a collar which is split longitudinally to form the halves.-

These halves constitute the'aforesaid centrifugal device and are situated between, and in contact with, the rear part of the carrier portion C and the front surface of the detonator'holder B so as to normally hold the needle 0 in the position shown out of contact with the detonator. The front surfaces otthe collar halves E, E may be rounded or bevelled as shown and the said halves are normally held inplace by an inertia sleeve, F having spring fingers bearing against the circumference of the lower parts otthe collar halves. These spring lingers are integral with the inertia sleeve as they are formed by making four or more longitudinal slits in thin ferrule extending from the sleeve, the length of these slits from the front end of the ferrule being varied in accordance with the inertia available. A distance ring F is ,provided between the inertia sleeve F and an internally projecting flange a on the nose A.

' The front face of the carrier portion .6 situated slightly to the rear of the front ,i'aoe ,oi' the nose A so as to leave a' sinall space between ,the said front face and a small shoulder or flange e on the nose A This, space is for the ,purpose of receiving the periphery of a closing disc .G which is made of slightly dished, form and is in serted with the convex side uppermost. The centre of the disc is then pressed rearwards andthis deforms the .disc so that the needle carrier is pressedagainst the collar halves E, E. This deformation of ,the disc does not increase its diameter and as it is a loose .fit the axial :hole of the ,nose A is iiree to move rearwards by air pressure. as aforesaid and also on impact'with an obstruction. A water-tight joint between the said disc and the axial hole in thenose A is hobtained by means of varnish after the disc has been ClOfOl nleClfiS stated above. The nse of-this disc prevents the possibility of [any Qvarnish or other water-proofing matenial coming in contact with the needle carrier.

, The parts of the ,fuse are normally in the position shown in the drawing with .the

needlecarrier supported by thecollar halves E, E and the shearing wire D out of contact with .theends of the elongated holes 0 lVhen theshell is fired from a gun, the .inertia sleeve F sets back and ,draws the spring fingers f, f clear of the collar halves E, E which are still supporting the needle the detonator, an inertia member norpantomime sa d devi n t reta n carrier so that the shearing wire D is still held out of contact withthe ends of the then causes the collar halves E, E toiiyout-w wardly by centrifugal force and the needle carrier is then no longer supported by these collar halves. The airpressureon the disc I G their causes it and the needle carrier to. move rearwards sl ghtly to bring the forward ends of the elongated holes .0 lightly into contact with the shearing wire D. Vhen an obstruction is met the needle carrier is movedforcihly rcarwards to bring the scribed the detonator .holder B is ri idly secured in the fuse body, it may besliel ably mounted therein and normally prevented from moving forwardly by centrifugal locking bodies; in the latter arrangement the detonator holder moves forward by momentrim to bring the detonator against the needle on impact or on graze of the shell when the needle carrier does not receive a direct blow.

H 'lV hat I claim and desire to secure by Letters Patent of the United States is 1. in a "shell fuse of the sensitive percussion type, the combination with the firing needle carrier, the detonator, the centrrifu gal retaining. device and the inertia member normally holding said device in the retain- Y position, of a light shearing wire 'pass-.

twolight netgal pre'ssings of cup shape fit- :tingpne within the other to form a hollow member, the needle being made inte 'ral with the rear pressing, a centrifugal ,dzvice for .iiclim yllcl ns' said 1 6 Of m -Q with the cle oaet ryan in rt m b r 9 .ma y h ding sa d d v i h i te m g Posi ion, an a l ght S ea in Wir Pa sing .flmei sh ole t e need car ie i l rg t an the iri es tha said ir no i e y lies .qu 'ef me w th th ront end said holes. I I

3- In .a h l of the s nsi i e Pe cu sionltype, the combination with the detonac a fi in n dl car i c mpo ed of inc-li h h tal re inss .O r s a tingfine within the other to form a hollow member, the ,needle being made integral with [theate mess g .acell n i l a ev for .i ormally holding said needleout of contact 11 0. 3. 0.1 by means-cf spring .fiq elt b. ,ng hef f sa db oa d a sh hearin wire passing through holes needle carrier ofdarger size than the wrreso that said wire irorinally lies out ,of contact w th the front ends of e holes.

{lQIii a .shell' fuse-of ,the sensitive permission type, the combination with t he elements claimed in claim 1, of a deformable disc of convex shape situated between the front surface of the needle carrier and an internal flange .or shoulder in an .axial hole in which thesaid needle carrier is disposed,

the said disc, when bent from its'convex shape, serving to press the needle carrier against the centrifugal device without increasing the diameter of the disc so that the latter remains free to be pressed rearwards on impact with an obstruction.

5. In a shell fuse of the sensitive percussion type, the combination with the elements claimed in claim 2, of a deformable disc of convex shape situated between the front surface of the needle carrier and an internal flange or shoulder in an axial hole in which the said needle carrier is disposed, the said disc, when bent from its convex shape, serving to press the needle carrier against the centrifugal device Without increasing the diameter of the disc so that the latter remains free to be pressed rearwards on impact with an obstruction.

6. In a shell fuse of the sensitive percussion type, the combination with the elements claimed in claim 3, of a deformable disc of convex shape situated between the front surface of the needle carrier and an internal flange or shoulder in an axial hole in which the said needle carrier is disposed, the said disc, when bent from its convex shape, serving to press the needel carrier against the centrifugal device without increasing the diameter of the disc so that the latter remains free to be pressed rearwards on impact with an obstruction.

7. In a shell fuse of the sensitive percussion type, the combination with the elements,

claimed in claim 1, of a pin in the nose of the fuse engaging in a recess formed in the needle carrier.

8. In a shell fuse of the sensitive percussion type, the combination with the elements claimed in claim 2, of a pin in the nose of the shell engaging in a recess formed in the rear metal pressing.

9. In a shell fuse of the sensitive percussion type, the combination with the elements claimed in claim 3, of a pin in the nose of the shell engaging in a recess formed in the rear metal pressing.

FREDERICK GEOFFREY LEES JOHNSON. 

